The Nazas River is a river located in northern Mexico, in the states of Coahuila and Durango. It is part of the endorheic Bolsón de Mapimí. It is only 560 kilometres (350 mi) long, but irrigates an area of 71,906 km2 (27,763 sq mi) in the middle of the desert. The Nazas is also nurtured by the San Juan, Ramos, Potreritos, del Oro, Nazas, Santiago, Tepehuanes and Peñón Blanco rivers. The river starts at the Sierra Madre Occidental. The aboriginal title for this stream is Tlahualilo, coming from the Nahuatl words tlalli meaning "fertile land" and ahualila, meaning "water for irrigation".